Cooling and energy loss of partially ionized hydrogen gas behind a shock wave

The problem discussed here is that of determining the motion of a cloud of neutral atomic hydrogen gas, when it is subjected to ionizing radiation from a star embedded in it. Initially the gas is in gravitational equilibrium at a constant temperature of about 100°K. It is supposed that at time t=0 the star suddenly begins to radiate with a certain intensity, which remains constant thereafter. Part of the surrounding gas will be ionized and an ionization front (separating the ionized gas from the neutral gas) will move outwards into the neutral gas. A shock wave may also propagate ahead of the ionization front into the neutral gas. There will therefore be two regions to consider—a region of ionized gas (HII region) and a region of neutral gas (HI region) in which there may be a shock.

Download Full-text

Enhanced energy loss of heavy ions passing a fully ionized hydrogen plasma

Laser and Particle Beams ◽

10.1017/s0263034600010314 ◽

1996 ◽

Vol 14 (4) ◽

pp. 599-604 ◽

Cited By ~ 3

Author(s):

R. Kowalewicz ◽

E. Boggasch ◽

D.H.H. Hoffmann ◽

J. Jacoby ◽

W. Laux ◽

...

Keyword(s):

Energy Loss ◽

Heavy Ions ◽

Electrical Discharge ◽

Hydrogen Plasma ◽

Hydrogen Gas ◽

Low Energy ◽

Stopping Power ◽

Electron Densities ◽

Singly Charged

Experiments are presented that demonstrate the high stopping power of fully ionized hydrogen plasma for low-energy heavy ions. A plasma with electron densities up to 7.1016 cm–3 at temperatures above 1 eV was created by an electrical discharge. In the described experiment, a stopping power of 1.08 GeV/(mg/cm2) was measured using singly charged krypton ions at 45–keV/u energy. The measured stopping power exceeds the corresponding value in cold hydrogen gas by a factor of 35. These measurements confirm the theoretical stopping power predictions close to the expected maximum in a fully ionized plasma.

Download Full-text

Energy loss of nuclear fragments in partially ionized materials of high atomic number

Physical Review A ◽

10.1103/physreva.44.392 ◽

1991 ◽

Vol 44 (1) ◽

pp. 392-395 ◽

Cited By ~ 3

Author(s):

R. A. Lewis ◽

G. A. Smith ◽

W. S. Toothacker

Keyword(s):

Energy Loss ◽

Atomic Number ◽

High Atomic Number ◽

Partially Ionized

Download Full-text

Electron Temperature Distribution across a Shock Wave in a Partially Ionized Gas

The Physics of Fluids ◽

10.1063/1.1692747 ◽

1969 ◽

Vol 12 (9) ◽

pp. 1830 ◽

Cited By ~ 3

Author(s):

S. S. R. Murty

Keyword(s):

Shock Wave ◽

Temperature Distribution ◽

Electron Temperature ◽

Ionized Gas ◽

Partially Ionized

Download Full-text

Measurement of stopping power of 240 MeV argon ions in partially ionized helium discharge plasma

Laser and Particle Beams ◽

10.1017/s0263034600184083 ◽

2000 ◽

Vol 18 (4) ◽

pp. 647-653 ◽

Cited By ~ 7

Author(s):

M. OGAWA ◽

U. NEUNER ◽

H. KOBAYASHI ◽

Y. NAKAJIMA ◽

K. NISHIGORI ◽

...

Keyword(s):

Energy Loss ◽

Electron Density ◽

Target Thickness ◽

Stopping Power ◽

Helium Plasma ◽

Discharge Ignition ◽

The Mean ◽

Argon Ions ◽

Partially Ionized ◽

Mean Charge

An energy loss of 240 MeV argon ions in a Z-pinch helium plasma has been for the first time observed throughout the entire pinching process. Standard Stark broadening analysis gives an electron density ranging from 4 to 6 × 1017 cm−3 during the pinch. To deduce stopping power from the energy loss, the target thickness of the helium plasma has been evaluated assuming the mean charge of helium based on thermal equilibrium. The observed electron density and the mean charge of helium give a target thickness of 30 ± 3 μg cm−2 from 1 μs to 1.8 μs after the discharge ignition. The measured stopping power exceeds a tabulated value for cold helium gas by a factor of 2 to 3 around the time of the first pinch. The experimental stopping power is compared with theoretical values calculated using an equation of stopping power for a partially ionized plasma.

Download Full-text